Selection for Growth Performance in Oreochromis niloticus Across Different Aquatic Environments Using Growth Hormone Gene Polymorphisms Fawzia S. Ali, Simone T. Awad, Mohamed Ismail, Shabaan A. Hemeda, Abeer F. El Nahas, et al. Animals, 2025 The current work focused on the molecular selection of Oreochromis niloticus with improved growth performance through marker-trait associations between SNPs within the growth hormone gene (GH) and growth performance. A total of 155 fish of the same age were collected from three locations (Lake Brullus (B), the River Nile at El-Qanater El-Khairia (Q), and Lake Nasser (A)). The selected individual progenies were evaluated through gene expression analysis for growth, inflammatory, nervous, and immune-related genes. A total of nine SNPs and three InDels were significantly associated with morphometric characteristics. The phenotypic variance (R2) of the detected SNPs ranged between 2.6% and 36%. The best populations were A and Q, as they recorded the best growth performance and harboured the highest number of SNPs and InDels, in addition to a significant increase in body weight and length. Furthermore, their progenies documented the most promising gene expression patterns of all tested genes. The current research highlights the importance of molecular selection and the potential use of population-specific SNPs in tilapia breeding programs.
Pterocladia capillacea polysaccharide enhances growth, immunity, digestive enzyme, antioxidant activities, and gene expressions of Litopenaeus vannamei Mohamed Ashour, Fawzia S. Ali, Ahmed Mamoon, Ahmed I. A. Mansour, Mohamed M. Mabrouk, et al. Frontiers in Marine Science, 2025 This work evaluated the effects of dietary supplementation with the seaweed polysaccharide (PS) extracted from red seaweed, Pterocladia capillacea, on the growth, feed efficiency, whole-body composition, immunological response, antioxidant activity, digestive enzyme activities, and gene expression of the whiteleg shrimp, Litopenaeus vannamei. Four isonitrogenous and isoenergetic diets with different SP levels were formulated. The basal experimental diet (control diet) had no seaweed polysaccharide added (PS0). Diets 2–4 (PS1, PS2, and PS3) were formulated to contain PS at levels of 1, 2, and 3 g/kg diet, respectively. Six hundred postlarvae (PLs15; with an initial body weight of 1.62 ± 0.12 g/PL) of the whiteleg shrimp L. vannamei were randomly selected and distributed into triplicate hapas per treatment. For the duration of the 60-day trial, the PLs were fed their corresponding diets three times a day at 10% of their body weight. Compared with those in the control diet and PS3, the shrimp reared in groups PS1 or PS2 showed significant (p< 0.05) improvements in the specific growth rate, survival rate, length gain rate, and weight gain rate. The individuals in the PS2 group showed the greatest significant (p< 0.05) values of the feed conversion ratio, feed efficiency ratio, and protein efficiency ratio. In addition, the shrimps in the PS2 group showed the highest significant values (p< 0.05) of lysozyme, amylase, lipase, and SOD, and the highest significant value of MDA, whereas the shrimp in the PS3 group showed the highest significant values (p< 0.05) of catalase. The expression levels of investigated growth-related genes (GH, IGF-1, and IGF-II) and immunity-related genes (Proph, SOD, and Lys) in the PS2 group were significantly (p< 0.05) increased. In conclusion, the supplementation rate of 2 g/kg PS significantly improved the growth, nutrient utilization efficiency, nonspecific immunity, antioxidant and digestive enzyme activities, and improved the immunity- and growth-related gene expression of L. vannamei shrimp. However, future works are recommended to understand the mechanism by which PS enhances physiological status and modulate genes expression in whiteleg shrimp.
A Novel Coelastrella tenuitheca Isolate Enhances Growth, Immunity, and Gene Expression in Whiteleg Shrimp Mohamed Ashour, Fawzia S. Ali, Ahmed Mamoon, Mohamed M. Mabrouk, Ahmed I. A. Mansour, et al. Aquaculture Nutrition, 2025 In this study, the freshwater microalga Coelastrella terrestris NIOF17/005 was utilized as a feed additive for the Pacific whiteleg shrimp (Litopenaeus vannamei). Coelastrella terrestris was characterized morphologically, phylogenetically (using 18s rRNA), and biochemically. Shrimp diets were supplemented with C. terrestris at 0, 1, 2.5, and 5 g/kg. After a 56‐day feeding trial, the biochemical analysis of C. terrestris revealed a composition of 38.12% protein, 37.82% lipids, and 15.75% carbohydrates, with valuable bioactive compounds including polyunsaturated fatty acids and antioxidant substrates. The supplementation of 2.5 g/kg C. terrestris significantly improved the growth performance of L. vannamei (10.23 g final weight), survival rate (92.67%), and feed conversion ratio (1.71). The whole‐body composition analysis of L. vannamei indicated enhanced protein content (59.74%) and lipid content (7.92%) in the algal‐supplemented groups in comparison to the control. Digestive enzyme activities of amylase and lipase increased significantly, with peak activities observed at 2.5 g/kg supplementation (49.55 and 60.06 IU/L, respectively). Nonspecific immunity parameters, including lysozyme (4.47 µg/mL), superoxide dismutase (SOD; 10.77 IU/g), and catalase (CAT; 10.47 IU/g) activities, were substantially elevated in shrimp‐fed C. terrestris‐supplemented diets, with optimal levels at 2.5 g/kg. The gene expression analysis showed that both studied growth‐related genes and immunity‐related genes were upregulated. These genes reached their maximum expression at a supplementation level of 2.5 g/kg, with the expression levels being approximately 2–3 times higher in the supplemented group in comparison to the control group. In conclusion, these findings suggested that the inclusion of C. terrestris NIOF17/005 (2.5 g/kg) into shrimp feed formulations could enhance productivity, improve shrimp health, and potentially increase the sustainability of shrimp farming operations.
Cyanobacteria Desertifilum tharense NIOF17/006 as a novel aquafeed additive: effect on the growth, immunity, digestive function, and gene expression of whiteleg shrimp postlarvae Mohamed Ashour, Ahmed Said Al-Souti, Ahmed Mamoon, Fawzia S. Ali, Mostafa E. Elshobary, et al. Frontiers in Marine Science, 2025 This work investigated the molecular identification and potential application of the cyanobacterial strain Desertifilum tharense NIOF17/006 as a novel aquafeed additive for whiteleg shrimp (Litopenaeus vannamei) postlarvae (PLs). Morphological and molecular characterization confirmed the isolate as D. tharense, with the 16S rRNA sequence analysis showing high similarity (98.01%–98.53%) to the known strains of D. tharense. Biochemical analysis revealed that the isolate contains 37.74% protein, 5.52% lipid, and 21.25% carbohydrate, on a dry weight basis. An 8-week feeding trial for L. vannamei PLs evaluated the effects of dietary supplementation with D. tharense NIOF17/006 at doses of 0, 1, 2.5, and 5 g/kg diet. Compared with shrimp in the control group, shrimp fed D. tharense-supplemented diets had significantly higher feed utilization, growth performance, survival rate, and whole body composition. The nonspecific immunity parameters (i.e., lysozyme, superoxide dismutase, and catalase), as well as the digestive enzyme activity of amylase and lipase, were significantly enhanced in shrimp fed diets supplemented with cyanobacteria, while the malondialdehyde (MDA) levels decreased. The gene expression analysis revealed the upregulation of growth-related genes (growth hormone, insulin-like growth factor I, and insulin-like growth factor II) and the immune-related genes prophenoloxidase (proPO), superoxide dismutase (SOD), and lysozyme (Lys) in shrimp muscles with increasing cyanobacteria supplementation, particularly at doses of 2.5–5 g/kg diet. Moreover, the polynomial regression machine learning model predicts that the ideal supplementation level of the probiotic cyanobacteria D. tharense NIOF17/006 ranges from 3.4 to 4.2 g/kg diet. This study demonstrates the potential of D. tharense NIOF17/006 as a promising aquafeed additive for improvement of the growth, immunity, and overall health of L. vannamei PLs, opening a new avenue for sustainable aquaculture practices.
Gender-specific responses in gene expression of Nile tilapia (Oreochromis niloticus) to heavy metal pollution in different aquatic habitats Simone T. Awad, Shabaan A. Hemeda, Abeer F. El Nahas, Eman M. Abbas, Mohamed A. S. Abdel-Razek, et al. Scientific Reports, 2024 Monitoring heavy metal accumulation is essential for assessing the viability of aquatic ecosystems. Our methodology involved integrating analysis of immunological, stress, inflammatory, and growth-related gene expression in male and female Nile tilapia with on-site recordings of physicochemical parameters. Additionally, we assessed the effect of different physicochemical parameters on heavy metal bioavailability and residual concentration in fish and water. Samples of fish and water were gathered from three different localities: Lake Brullus, a brackish lake sited in northern Egypt; Lake Nasser, an artificial freshwater reservoir located in southern Egypt; and El-Qanater El-Khayria, a middle-freshwater location belonging to the Rashid branch of the river Nile. The assessment of heavy metal residues (Fe, Cu, Zn, Mn, and Ni) revealed that their concentrations were higher in fish specimens compared to their counterparts in water (except for Ni). In addition, Lake Brullus emerges as the most polluted area, exhibiting elevated levels of heavy metals concentrations in water and fish specimens. In contrast, Lake Nasser showed the least degree of heavy metals pollution. Gene expression analysis revealed gender-specific responses to heavy metal exposure at the three investigated water bodies. The expression of hepatic antioxidant genes (GST and MT) and inflammatory-related genes (CC-chemokine and TNFα) increased in males compared to females. In females, the immune and pro-inflammatory-related genes (IgM and CXC2-chemokine) transcripts were upregulated. Additionally, growth-related genes were downregulated in both Lake Brullus and El-Qanater; on the contrary, fish samples from Lake Nasser exhibited a normal expression pattern of growth-related genes. Stress-related genes (HSP70 and HSP27) showed significant downregulation in gills of both genders from Lake Brullus. The minimal presence of heavy metal contaminants in Lake Nasser seems to endorse the normal patterns of gene expression across all gene categories. A potential gender-specific gene expression response towards pollution was noticed in genes associated with inflammation and antioxidant activities. This highlights the importance of considering gender-related responses in future environmental assessments.
